PMO-70: STUDY OF POTENTIAL DRUG INTERACTION BETWEEN Thalassia testudinum BM-21 EXTRACT AND SOME DRUGS ACTING IN CNS: A PRECLINICAL STUDY

Introduction: Herbal medicine may cause significant toxicity with additive, synergistic or antagonistic effects when taken in combination with allopathic drugs. BM-21 is the extract from the sea grass Thalassia testudinum standardized to thalassiolin B (5.8 ± 0.9%) that has promising memory enhanced and antitumoral activities. In vitro and in vivo experiments have showed that BM-21 and thalassiolin B can modulate the activity and expression of P450 (CYP) enzymes. The potential interaction between BM-21 with diazepam, imipramine and thiopental was investigated on 2-week, oral, once daily administration in mice. Material and Methods: Healthy OF-1 male mice were divided in to eight groups of ten each. Control group I was administered distilled water. Group II received diazepam (5 mg/kg) or imipramine (15 mg/kg). Group III, IV and V received BM-21 (40, 100 and 400 mg/kg), while Groups VI and VII and VIII received the extract and single oral administration of diazepam and imipramine 30 min prior to experiment. Open field (OF), rota rod behavior (RRB), tail suspension test (TST) and maximal electro-shock seizure (MES) were evaluated. In Thiopental Sleeping Time test, a control group I administered with thiopental and groups II, III and IV that received BM-21 and thiopental (60 mg/kg s.c, 60 min after the last administration) were used. Results: In TST and MES there was no change in immobility time and duration of maximal convolutions neither in groups III, IV and V compared to control nor in groups VI, VII and VIII compared with with imipramine and diazepam, respectively. In thiopental sleeping time there was a significant reduction of sleeping time in groups II, III and IV when compared with the control. When BM-21 was administered alone, there was not effect on locomotor activity and motor coordination. This indicates non-sedative and non-tranquillizing properties. Conclusi-ons: BM-21 does not possess antidepressant-like and anticonvulsant effect. Results also revealed no interac-tion between BM-21 and diazepam/imipramine. How-ever, according to the effects in pharmacological models assayed in the present work, the reduction of sleeping time suggest an interaction of BM-21 with thiopental that seems to be of pharmacokinetic nature.